Term
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Definition
| a rock is a naturally occurring aggregate of minerals and rock fragments |
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Term
| name the 6 major geologic principles |
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Definition
horizontality
superposition
uniformitarianism
inclusions
lateral extension
cross-cutting relationships |
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Term
principle of superposition
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Definition
in a vertical sequence of sedimentary or volcanic rock
the higher unit is younder than the lower one
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Term
principle of original horizontality
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Definition
rock laters were originally deposited close to horizontal
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Term
| principle of lateral extension |
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Definition
a rock unit continues laterally unless there is a structure or change
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Term
| princliple of cross-cutting relations |
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Definition
| a sctructure that crosses another is younger than the structure cut |
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Term
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Definition
| a structure included in another is older |
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Term
| principle of uniformitarianism |
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Definition
process operating in the past were constrained by the laws of physics we know today
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Term
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Definition
· Talc
· Gypsum
· Calcite (finger nail)
· Fluorite
· Apatite (knife blade)
· Orthoclase
· Quartz (steel file)
· Topaz
· Corundum
· Diamond
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Term
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Definition
developed by krumbein
phi=-log2d (d=diameter in mm)
boulders (-8), rebble (-6), sand (-1), silt (4), clay (8)
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Term
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Definition
| the theory that the earth's crust is composed of plates that move acrosss the mantle by convection, heat flow, and magnetism. plate movement causes spreading (divergent), subduction and lifting (convergent), and shearing (transform) |
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Term
| 4 piecesn of scientific evidence which support plate tectonics |
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Definition
1. fossils found that link continents together at one time
2. mid ocean ridges, evidence of expansion due to magnetic symmetrical alignment of iron found in rocks
3. mountains are found at convergent land boundaries
4. the oldest rock in the ocean are found farthest from the rift zones
5. volcanoes (ring of fire) |
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Term
| why should petroleum engineers need to understand plate tectonics |
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Definition
in order to find where the best resources within the earth. knowing where subductions zones are and other things about PT help us know where to look for oil
to understand what has happened over time to a formation, which gives clues about traps and faulting where we find hydrocarbons |
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Term
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Definition
rocks formed by the solidification (cooling) of magma
composition: acidic (quartz and k-spars), basic (olivine, hornblende, plag-feldspar) |
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Term
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Definition
rocks changed from igneous/sedimentary rocks by pressure/temperature
foliated: aligned textures
non-foliated: no preferred mineral alignment
texture often geerated by crystal re-growth in an applied stress field or by shearing of existing cystals |
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Term
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Definition
| rocks derived from debris of other rocks and accumulate at the earth's surface at normal temperature and pressure |
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Term
| major process involved in formation of sedimentary rocks |
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Definition
- phsyical and chemical weathering
- transporations by running water, wind, gravity, and ice
- deposition in a sedimentary basin
- compaction and cementation of sediment into a solid rock
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Term
| composition of sedimentary rocks |
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Definition
highly variable since they come from other rocks
major consituents: quartz, calcite, clay, rock fragments |
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Term
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Definition
horizontal layers
cross-bedding - indicates currect direction |
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Term
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Definition
clastic: crystalline
-rounding, sorting, cementation, grain size
carbonate:
-oolitic, skeletal |
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Term
| list 4 properties of sediments that control the performance of reservoirs |
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Definition
grain size
cementation
sorting
rounding |
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Term
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Definition
diameter of grains of rock in the reservoir
affects permeability
approximately 10 times that of pore size |
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Term
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Definition
precipitation of minerals or clays within a rock
reduces premeability |
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Term
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Definition
| well sorted rocks have higher porosities |
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Term
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Definition
roundness of grains affects packing
well rounded = higher porosity |
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Term
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Definition
sand: (2mm to 1/16mm)
silt: (1/16mm to 1/256mm)
clay: (1/256mm and below) |
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Term
| younger sandstones vs older sandstones |
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Definition
younder sandstones will be less cemented and consolidated and will have a higher porosity than older sandstones
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Term
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Definition
sedimentary deposits that act as solids when settled, but as fluids when agitated
they can lay on continental slopes, and are deposited on abyssal plain |
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Term
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Definition
type of clay
library books |
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Term
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Definition
type of clay
grassy, hairs |
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Term
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Definition
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Term
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Definition
has a gas-oil-water column
pooled accumulation |
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Term
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Definition
- no gas-oil-water column
- distributed throughout rock
- special production techniques
- ex: tar sands, heavy oil, coal bed, methane, oil shale, gas hydrates
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Term
| how can knowledge of a depositional environment help you exploit a reservoir |
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Definition
- it provides information of grainsize which gives insight to permeability and porosity
- gives information on the stability of the reservoir, level of compaction and cementation
- gives info on ordanic matter that could be there
- environmental constraints provide direction for exploitation
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Term
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Definition
| reservoirs are where hydrocarbons adre stored. they contain traps which seal hydrocarbons in, preventing them from migrating further |
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Term
| how do hydrocarbons get in reservoirs? |
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Definition
they are generated from the source rock, which contains organic matter at the right temperature and pressure.
they migrate through the rock until they are sealed in a trap in a reservoir |
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Term
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Definition
composed of clay and small amounts of quartz
grain size is less than 1/256mm |
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Term
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Definition
| obtained from experiments |
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Term
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Definition
| gel to liquid when shaken |
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Term
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Definition
appearing of found everywhere
very common |
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Term
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Definition
| use to classify clasic sedimentary rocks |
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